The female Obama is far more popular than her husband, the President. About two-thirds of Americans have a favorable view of Michelle Obama, according to a recent Gallup survey. That's 14 points higher than Barack Obama received in the same poll. (Results here)

Philadelphia is friendly territory for the Obama campaign, it's the place where the Democrats' Pennsylvania base resides. It makes sense that the campaign would dispatch the popular First Lady, who is currently out promoting her new book, “American Grown: The Story of the White House Kitchen Garden and Gardens Across America."

In an interview with Jon Stewart on The Daily Show on Tuesday night, Stewart teased her about being the more popular one, saying she should use it as leverage over the president in marital disputes.